|  | /* | 
|  | * linux/arch/arm/mach-omap1/time.c | 
|  | * | 
|  | * OMAP Timers | 
|  | * | 
|  | * Copyright (C) 2004 Nokia Corporation | 
|  | * Partial timer rewrite and additional dynamic tick timer support by | 
|  | * Tony Lindgen <tony@atomide.com> and | 
|  | * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com> | 
|  | * | 
|  | * MPU timer code based on the older MPU timer code for OMAP | 
|  | * Copyright (C) 2000 RidgeRun, Inc. | 
|  | * Author: Greg Lonnon <glonnon@ridgerun.com> | 
|  | * | 
|  | * This program is free software; you can redistribute it and/or modify it | 
|  | * under the terms of the GNU General Public License as published by the | 
|  | * Free Software Foundation; either version 2 of the License, or (at your | 
|  | * option) any later version. | 
|  | * | 
|  | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED | 
|  | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | 
|  | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN | 
|  | * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | 
|  | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | 
|  | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF | 
|  | * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON | 
|  | * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | 
|  | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | 
|  | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 
|  | * | 
|  | * You should have received a copy of the  GNU General Public License along | 
|  | * with this program; if not, write  to the Free Software Foundation, Inc., | 
|  | * 675 Mass Ave, Cambridge, MA 02139, USA. | 
|  | */ | 
|  |  | 
|  | #include <linux/kernel.h> | 
|  | #include <linux/init.h> | 
|  | #include <linux/delay.h> | 
|  | #include <linux/interrupt.h> | 
|  | #include <linux/spinlock.h> | 
|  | #include <linux/clk.h> | 
|  | #include <linux/err.h> | 
|  | #include <linux/clocksource.h> | 
|  | #include <linux/clockchips.h> | 
|  | #include <linux/io.h> | 
|  | #include <linux/sched_clock.h> | 
|  |  | 
|  | #include <asm/irq.h> | 
|  |  | 
|  | #include <asm/mach/irq.h> | 
|  | #include <asm/mach/time.h> | 
|  |  | 
|  | #include "hardware.h" | 
|  | #include "mux.h" | 
|  | #include "iomap.h" | 
|  | #include "common.h" | 
|  | #include "clock.h" | 
|  |  | 
|  | #ifdef CONFIG_OMAP_MPU_TIMER | 
|  |  | 
|  | #define OMAP_MPU_TIMER_BASE		OMAP_MPU_TIMER1_BASE | 
|  | #define OMAP_MPU_TIMER_OFFSET		0x100 | 
|  |  | 
|  | typedef struct { | 
|  | u32 cntl;			/* CNTL_TIMER, R/W */ | 
|  | u32 load_tim;			/* LOAD_TIM,   W */ | 
|  | u32 read_tim;			/* READ_TIM,   R */ | 
|  | } omap_mpu_timer_regs_t; | 
|  |  | 
|  | #define omap_mpu_timer_base(n)							\ | 
|  | ((omap_mpu_timer_regs_t __iomem *)OMAP1_IO_ADDRESS(OMAP_MPU_TIMER_BASE +	\ | 
|  | (n)*OMAP_MPU_TIMER_OFFSET)) | 
|  |  | 
|  | static inline unsigned long notrace omap_mpu_timer_read(int nr) | 
|  | { | 
|  | omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr); | 
|  | return readl(&timer->read_tim); | 
|  | } | 
|  |  | 
|  | static inline void omap_mpu_set_autoreset(int nr) | 
|  | { | 
|  | omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr); | 
|  |  | 
|  | writel(readl(&timer->cntl) | MPU_TIMER_AR, &timer->cntl); | 
|  | } | 
|  |  | 
|  | static inline void omap_mpu_remove_autoreset(int nr) | 
|  | { | 
|  | omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr); | 
|  |  | 
|  | writel(readl(&timer->cntl) & ~MPU_TIMER_AR, &timer->cntl); | 
|  | } | 
|  |  | 
|  | static inline void omap_mpu_timer_start(int nr, unsigned long load_val, | 
|  | int autoreset) | 
|  | { | 
|  | omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr); | 
|  | unsigned int timerflags = MPU_TIMER_CLOCK_ENABLE | MPU_TIMER_ST; | 
|  |  | 
|  | if (autoreset) | 
|  | timerflags |= MPU_TIMER_AR; | 
|  |  | 
|  | writel(MPU_TIMER_CLOCK_ENABLE, &timer->cntl); | 
|  | udelay(1); | 
|  | writel(load_val, &timer->load_tim); | 
|  | udelay(1); | 
|  | writel(timerflags, &timer->cntl); | 
|  | } | 
|  |  | 
|  | static inline void omap_mpu_timer_stop(int nr) | 
|  | { | 
|  | omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr); | 
|  |  | 
|  | writel(readl(&timer->cntl) & ~MPU_TIMER_ST, &timer->cntl); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * --------------------------------------------------------------------------- | 
|  | * MPU timer 1 ... count down to zero, interrupt, reload | 
|  | * --------------------------------------------------------------------------- | 
|  | */ | 
|  | static int omap_mpu_set_next_event(unsigned long cycles, | 
|  | struct clock_event_device *evt) | 
|  | { | 
|  | omap_mpu_timer_start(0, cycles, 0); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int omap_mpu_set_oneshot(struct clock_event_device *evt) | 
|  | { | 
|  | omap_mpu_timer_stop(0); | 
|  | omap_mpu_remove_autoreset(0); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int omap_mpu_set_periodic(struct clock_event_device *evt) | 
|  | { | 
|  | omap_mpu_set_autoreset(0); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static struct clock_event_device clockevent_mpu_timer1 = { | 
|  | .name			= "mpu_timer1", | 
|  | .features		= CLOCK_EVT_FEAT_PERIODIC | | 
|  | CLOCK_EVT_FEAT_ONESHOT, | 
|  | .set_next_event		= omap_mpu_set_next_event, | 
|  | .set_state_periodic	= omap_mpu_set_periodic, | 
|  | .set_state_oneshot	= omap_mpu_set_oneshot, | 
|  | }; | 
|  |  | 
|  | static irqreturn_t omap_mpu_timer1_interrupt(int irq, void *dev_id) | 
|  | { | 
|  | struct clock_event_device *evt = &clockevent_mpu_timer1; | 
|  |  | 
|  | evt->event_handler(evt); | 
|  |  | 
|  | return IRQ_HANDLED; | 
|  | } | 
|  |  | 
|  | static __init void omap_init_mpu_timer(unsigned long rate) | 
|  | { | 
|  | if (request_irq(INT_TIMER1, omap_mpu_timer1_interrupt, | 
|  | IRQF_TIMER | IRQF_IRQPOLL, "mpu_timer1", NULL)) | 
|  | pr_err("Failed to request irq %d (mpu_timer1)\n", INT_TIMER1); | 
|  | omap_mpu_timer_start(0, (rate / HZ) - 1, 1); | 
|  |  | 
|  | clockevent_mpu_timer1.cpumask = cpumask_of(0); | 
|  | clockevents_config_and_register(&clockevent_mpu_timer1, rate, | 
|  | 1, -1); | 
|  | } | 
|  |  | 
|  |  | 
|  | /* | 
|  | * --------------------------------------------------------------------------- | 
|  | * MPU timer 2 ... free running 32-bit clock source and scheduler clock | 
|  | * --------------------------------------------------------------------------- | 
|  | */ | 
|  |  | 
|  | static u64 notrace omap_mpu_read_sched_clock(void) | 
|  | { | 
|  | return ~omap_mpu_timer_read(1); | 
|  | } | 
|  |  | 
|  | static void __init omap_init_clocksource(unsigned long rate) | 
|  | { | 
|  | omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(1); | 
|  | static char err[] __initdata = KERN_ERR | 
|  | "%s: can't register clocksource!\n"; | 
|  |  | 
|  | omap_mpu_timer_start(1, ~0, 1); | 
|  | sched_clock_register(omap_mpu_read_sched_clock, 32, rate); | 
|  |  | 
|  | if (clocksource_mmio_init(&timer->read_tim, "mpu_timer2", rate, | 
|  | 300, 32, clocksource_mmio_readl_down)) | 
|  | printk(err, "mpu_timer2"); | 
|  | } | 
|  |  | 
|  | static void __init omap_mpu_timer_init(void) | 
|  | { | 
|  | struct clk	*ck_ref = clk_get(NULL, "ck_ref"); | 
|  | unsigned long	rate; | 
|  |  | 
|  | BUG_ON(IS_ERR(ck_ref)); | 
|  |  | 
|  | rate = clk_get_rate(ck_ref); | 
|  | clk_put(ck_ref); | 
|  |  | 
|  | /* PTV = 0 */ | 
|  | rate /= 2; | 
|  |  | 
|  | omap_init_mpu_timer(rate); | 
|  | omap_init_clocksource(rate); | 
|  | } | 
|  |  | 
|  | #else | 
|  | static inline void omap_mpu_timer_init(void) | 
|  | { | 
|  | pr_err("Bogus timer, should not happen\n"); | 
|  | } | 
|  | #endif	/* CONFIG_OMAP_MPU_TIMER */ | 
|  |  | 
|  | /* | 
|  | * --------------------------------------------------------------------------- | 
|  | * Timer initialization | 
|  | * --------------------------------------------------------------------------- | 
|  | */ | 
|  | void __init omap1_timer_init(void) | 
|  | { | 
|  | omap1_clk_init(); | 
|  | omap1_mux_init(); | 
|  |  | 
|  | if (omap_32k_timer_init() != 0) | 
|  | omap_mpu_timer_init(); | 
|  | } |